This invention relates generally to electric lamps, particularly to those for use on motor vehicles as, for example, headlamps, and more particularly to vehicles lamps of the type having a reflector extension or an inner lens in a lighting chamber defined by a lamp body and a lens. Still more particularly, the invention deals with how to mount such an inner member in the lighting chamber.
The vehicle headlamp has been known and used extensively wherein a light source together with a reflector is mounted in a lighting chamber formed by bonding a lens to the open front end of a lamp body. It has also been common with this type of headlamp to mount a reflector extension between lens and reflector in the lighting chamber. Approximately in the shape of a short tube, the reflector extension is intended to conceal the gaps between lamp body and reflector. Heretofore, the reflector extension has been mounted in the lighting chamber by having its top and bottom marginal edges screwed to the top and bottom rims of the lens turned rearwardly therefrom.
An objection to this conventional method of reflector extension mounting is that it requires screws or like fasteners, which add to lamp parts and which make lamp assemblage very troublesome and time-consuming. Another objection is that the fasteners, particularly those fixing the reflector extension to the top rim of the lens, are visible from above the lamp when the automobile hood is opened. The externally visible fasteners are undesirable from an esthetic point of view.
The same objections hold true with those vehicular headlamps in which an inner lens is fastened interiorly of the above mentioned lens with a view to beam pattern control. The invention is equally well applicable to electric lamps having a reflector extension, to those having an inner lens, or those having both. Therefore, hereinafter in this specification, the generic name "inner member" will be used where necessary to mean either the reflector extension, the inner lens, or any other essentially equivalent part.